'Walking Dead' Season 9 premiere is lowest-rated in series history

Michonne (Danai Gurira, center) and the other survivors of All-Out War on the first episode of Season 9 of "The Walking Dead."

Michonne (Danai Gurira, center) and the other survivors of All-Out War on the first episode of Season 9 of "The Walking Dead." (Jackson Lee Davis/AMC / TNS)

Joe OttersonVariety

“The Walking Dead" returned for its ninth season on Sunday down significantly in the Live+Same Day ratings.

According to Nielsen data, the AMC series drew a 2.5 rating in adults 18-49 and 6.1 million viewers. That is the lowest rating in adults 18-49 since the show began, with the previous low being a 2.7 for the series premiere. However, that episode drew only 5.4 million viewers. The Season 9 premiere was also down approximately 50% in the key demo and 47% in total viewers compared to the Season 8 opener, which drew a 5.0 and 11.4 million viewers last year.

This season's premiere is also flirting with a tie for the series low in the key demo, which was a 2.4 set back during Season 1.

From the Season 8 finale, the premiere was down approximately 23% in total viewers and 27% in the key demo. It was also down double digits from the Season 8 Live+Same Day average, which was a 3.4 and 7.8 million viewers.

"The Walking Dead" was still the top-rated show on cable for Sunday night by a wide margin. Nevertheless, the show is currently not the top-rated show on all of TV, coming up short of NBC's "This Is Us," which is averaging a 2.7 after two episodes this season.

According to AMC, the premiere also drove the single highest day of new sign-ups in the history of AMC Premiere, the network's commercial-free upgrade option. Delayed viewing numbers for the show will be available Friday.